Macrotarsius is an extinct genus of omomyid that inhabited North America and East Asia during the Eocene epoch. Taxonomy. "Macrotarsius" contains five species: the type species "M. montanus", "M. jepseni", "M. macrorhysis", "M. roederi", and "M. siegerti". Distribution. "Macrotarsius macrorhysis" lived in Jiangsu, China during the Middle Eocene.